Docopt only proceedes when an optional part is given

Question

I'm trying to learn pythons docopt module and have the following simple script:

""" Usage:
rsnapshot-once [-c CFGFILE] (sync|hourly|daily|monthly)

    -c CFGFILE  specify the configfile that rsnapshot should use
"""

import logging
import sys

from docopt import docopt

args = docopt(__doc__, version='0.0.1-alpha')

logging.basicConfig(stream=sys.stdout, level=logging.DEBUG, formatter=logging.BASIC_FORMAT)
logging.debug("Parsed arguments:\n" + str(args));

if not args.get("-c"):
    args['CFGFILE'] = "/etc/rsnapshot.conf"

When invoked from the command line with the -c option:

% ./rsnapshot-once.py -c someconfigfile sync                                                                
DEBUG:root:Parsed arguments:
{'-c': True,
 'CFGFILE': 'someconfigfile',
 'daily': False,
 'hourly': False,
 'monthly': False,
 'sync': True}

When only the command is passed:

% ./rsnapshot-once.py daily                                                                               
Usage:
        rsnapshot-once [-c CFGFILE] (sync|hourly|daily|monthly)

It seems, that I am misunderstanding something. Could anyone give me a hint, what I'm doing wrong?

Thanks

Answer 1

I got it working. Finally the problem was that I used tabs to format my usage docstring:

"""
\t\t\tUsage:
\t\t\trsnapshot-once [-c CFGFILE] (sync|hourly|daily|monthly)

\t\t\tOptions:
\t\t\t-c CFGFILE        specify the configfile that rsnapshot should use
"""

When I change this to be:

"""
            Usage:
            rsnapshot-once [-c CFGFILE] (sync|hourly|daily|monthly)

            Options:
            -c CFGFILE      specify the configfile that rsnapshot should use
"""

It works fine...

There is a similar issue I found after I figured out what the problem was: https://github.com/docopt/docopt/issues/368

EDIT: While from a functional point of view, the arguments are parsed correctly when no tabs are used. But in case the call is wrong, only the "Usage:"-Part of the docstring is printed. The "Options:"-Part is not. Can any of you confirm that?

For example, compare those variants:

1a. Valid call

1b. Invalid call(option part is not printed)

2a. Valid call (but not working)

2b. Invalid call (Text is printed as expected)

Answer 2

The example you have given works here. So maye it has something to do with the docopt version you are using. Regarding the notation you are almost on the right track, only some small details are missing.

Before the options, there should be a line that says "Options:". Docopt looks for this, and interprets the lines after. In the options part it is possible to set default values for options too.

Here is an example:

"""Usage:
  rsnapshot-once [-c CFGFILE] (sync|hourly|daily|monthly)

Options:
  -c CFGFILE  specify the configfile that rsnapshot should use 
              [default: /etc/rsnapshot.conf]
"""

Then the user will also see what the default value is.